As we eagerly await Season Six of The Walking Dead to learn what happens to the Alexandria Not-So-Safe-Zone and the inevitable Rick/Morgan showdown, let's take a moment to reflect on the most memorable titular characters of the series.

These aren't the walkers who merely shambled by in the backgrounds of crowd scenes – no, we're talking about the more creatively imagined, creepier-than-usual or the straight-up bloodcurdling zombies that we can't get out of heads. These are the ones that broke our hearts (oh, Penny!) and made us lose our lunches. There have been hundreds of rotting corpses who's strut and fretted across the hit show's stage. These are the walking dead who still haunt our dreams, one clawing hand and chomping jaw at a time.

(If you're not caught up on The Walking Dead, stop reading right now. This list is only for the fans who are ready for the season premiere on October 11th. Spoilers abound. You've been warned.)

Dead Shane (Season 2, Episode 12: ‘Better Angels’)

The death of Rick's right-hand man and former partner was a shocker, although we sort of knew the two alpha males would eventually. By the end of the second season, Shane was beginning to genuinely lose his shit and generally trying to usurp power over the survivors at Hershel's farm. So during a kill-or-be-killed fracas, Rick stabs Shane — and our hero finally sees proof that everyone comes back from the dead, bitten or not. Even more than the various dangling-organs walkers and head-squished monstrosities we'd come across by then, the sight of a major character we'd gotten to know intimately over two seasons — even in shaved-head psycho mode — turning into one of the undead was genuinely disturbing. And it wouldn't be the last time…

Penny (Season 3, Episode 8: ‘Made to Suffer’)

The Governor's daughter! The eye-patched villian refuses to accept that his turned child, Penny, is a lost cause; he keeps her caged up in his evil mancave, feeding her raw meat and brushing her hair (while also removing bits of her scalp). Then Michonne discovers the child and attempts to free her, until she realizes the little girl is, well…she's not doing so hot anymore. Penny bites the dust (a second time), as does whatever humanity the Governor had left. When characters kept walkers as leashed pets, they tended to cut off their arms and jaws; here, the child is the last hope that the undead will eventually return to their old selves. Penny may not be the most gut-wrenching zombie on the show, true. But she is one of the most heartwrenching.

Drowned Food Pantry Zombie (Season 5, Episode 2: ‘Strangers’)

Gabriel leads a group to the county food bank to scavenge for supplies. Bob is still chirping about being optimistic because sure, they're stuck in a nightmare — but nightmares always end, right? Then he plunges into the flooded basement of the food pantry, and a disgusting, disintegrating, decomposing zombie manages to chomp Bob right on the ankle. So walkers definitely don't drown, and they still want to eat brains even when their bodily tissues are barely connected. Duly noted.

Overgrown Tree Zombie (Season 4, Episode 3: ‘Isolation’)

In the midst of Season Four's prison-plague, Hershel decides to go foraging for healing elderberries, claiming that everything is safe in the woods. Right, except for that one immobile walker who's been decomposing on the ground for so long that a tree has already started growing around him, roots and all. (Technically half a zombie, actually.) Without its legs, this not-to-able-to-go-walking dead got stuck in the muck long enough for a tree to consume it. Think about that – the zombie-apocalypse has lasted so long that trees are now growing around and through these reanimated bodies. [Shudder]

Mud Zombie (Season 4, Episode 8: ‘Too Far Gone’)

After Penny's unfortunate demise, the Governor finds a surrogate daughter in Meghan, and when he goes gallivanting off to threaten Rick's crew, she makes mud pies on the banks of a river. Except this is the zombie apocalypse, which means that a flash flood probably caught a zombie with missing teeth and no skin, and he's probably buried right in the very spot you're digging in. Let this be a lesson to you, kids.

Hanging Tree Zombie (Season 2, Episode 3: ‘Save the Last One’)

Andrea and Daryl stumble upon a gruesome sight in the woods – a hanging zombie and a poem of despair: "Got bit. Fever hit. World gone to shit. Might as well quit." Seems this guy tried to off-himself but didn't quite know about the "aim for the brain" rule — and naturally reanimated while still hanging in his own noose. And of course, other zombies gnawed off his lower half.

C-Section Zombie (Season 3, Episode 2: ‘Sick’)

Pregnant Lori knows her baby will need to be delivered via C-section; Carol knows that, because Hershel is still recovering from hiszombie-bite/amputation/near-death experience, she'll be the one helping with the delivery. Thank goodness, there are lots of (walking) cadavers around, so Carol takes the initiative and takes down a female zombie, dragging its body into the prison for some gross anatomy lessons.We got a little queasy just writing that last sentence.

Lori-Eating Zombie (Season 3, Episode 5: ‘Say the Word’)

Life in the zombie-infested prison is far from an ideal place to give birth; this is a fact, people. After Lori delivers her baby, she dies. (She doesn't have time to become a zombie because her son Carl shoots her in the head.) Then a bereft Rick tries to track the corpse down and discovers what happened to his spouse, via a Lori-Eating Zombie so stuffed that it can no longer move. An entire woman’s body in one walker's tummy. How horrific.

Bloated Well Zombie (Season 2, Episode 4: ‘Cherokee Rose’)

This is one zombie we can never un-see. The folks at Hershel's farm were about to draw water from the well when Dale noticed a walker splashing around in the well. The group decided that shooting the zombie would certainly taint the water with walker-guts so they tried to trap it instead. Except this particular member of the wading dead – sodden, turgid, swollen — did not go for their bait of canned ham. So they sent Glenn into the well to try to trap him; no one had counted on this bloated beast splitting in half, however, polluting the water with its goopy innards. Ugh.

Little Girl Zombie (Season 1, Episode 1: ‘Days Gone By’)

Because you never forget your first. Having just left the hospital, Rick spots a tiny tot wearing an adorable pink nightgown clutching a teddy bear. "Little girl, little girl," he calls. The child wheels her head around to reveal half a jaw and a deathly pallor; she lurches towards him, intent on eating his brain. (It's a nice shout-out to that legendary Night of the Living Dead scene of an unfortunate family reunion.) No matter how many other walkers we'd meet on the group's travels over the next five seasons, there's something about the primal shock of seeing this initial zombie that still resonates. We have seen the horror to come, and they look just like our kids. And thus our Walking Dead waking nightmare begins.